The striking colors of some lizards, especially blue ones, often lead to questions about their potential danger. Many people wonder if these vibrant creatures are poisonous. The term “poisonous” is frequently used broadly, but in biology, it has a distinct meaning that clarifies whether a blue lizard, or any lizard, poses a threat. This article will explore the scientific truth behind this common misconception.
Distinguishing Poisonous from Venomous
Understanding the difference between “poisonous” and “venomous” is fundamental to assessing the danger posed by an animal. An animal is considered poisonous if it contains toxins harmful when ingested or absorbed through skin contact. A classic example is the poison dart frog, which secretes toxins on its skin that can be harmful if touched or eaten. These animals use toxins to deter predators.
In contrast, an animal is venomous if it actively injects toxins into another organism, usually through a bite or a sting. Snakes, spiders, and scorpions are common examples of venomous creatures, as they deliver their toxins directly into a wound. The key distinction is delivery method: poisonous means harmful if you eat or touch it, while venomous means harmful if it bites or stings you. Very few lizards are truly venomous, and none are genuinely poisonous in the way many people commonly understand the term.
Common Blue-Colored Lizards
Most blue-colored lizards encountered in nature are not dangerous to humans. One well-known example is the blue-tongued skink, found in Australia and New Guinea. These skinks are neither venomous nor poisonous, though they may display their bright blue tongue as a bluff-warning. They are generally docile, can reach lengths of up to 24 inches, and primarily eat insects, fruits, and vegetables. While they can deliver a painful bite if provoked, it is not venomous.
Another species is the blue anole (Anolis gorgonae), a small, purely blue lizard found exclusively on Gorgona Island, Colombia. Both sexes exhibit this vibrant blue coloration. These arboreal lizards are not harmful to humans. Similarly, the electric blue gecko (Lygodactylus williamsi), an endangered species from Tanzania, is known for the brilliant blue coloration of its males. These tiny geckos are insectivorous and pose no threat to humans.
Blue-tailed skinks, such as the juvenile Western Skink or Five-lined Skink, feature a striking blue tail that fades with age. While there are anecdotal reports of mild toxicity to pets if ingested, these lizards are not poisonous to humans and their bites are not dangerous. The bright blue tail serves as a distraction, allowing the lizard to escape predators by detaching its tail. The only lizards known to be truly venomous are the Gila monster and the Mexican beaded lizard, neither of which are typically blue. These two species, found in the southwestern US, Mexico, and Guatemala, deliver venom through grooved teeth. While their bites are painful, they are rarely fatal to healthy adult humans.
Encountering Lizards Safely
When encountering any lizard in the wild, the safest approach is to observe from a distance. Wild lizards are typically shy and will attempt to flee if approached. Avoid attempting to handle or provoke them. Handling can cause stress to the animal and may result in a defensive bite, even from a non-venomous species.
If a lizard enters a home, guide it gently back outside instead of capturing it directly. For larger or unknown species, contacting local animal control or a wildlife expert is recommended for safety. Bites from most lizards are rare and occur primarily as a defensive response when they feel threatened or cornered. Washing hands after any contact with reptiles or their environment is advisable.